With the 2011 return, the campaign says, will be "a notarized letter from the Romneys' tax preparer, PricewaterhouseCoopers, LLP (PWC), giving a summary of tax rates from the Romneys' tax returns for the 20-year period of 1990-2009." That, says the campaign, will state that the Romneys' "average annual effective federal tax was 20.20 percent" over those 20 years.

Romney previously released his 2010 returns, but has declined to go back further. The Senate's top Democrat, Harry Reid of Nevada, famously said this summer that he's been told by an unnamed source that Romney paid no income taxes over the past decade and should release returns from more years. Romney rejected that charge, and PricewaterhouseCoopers' statement is a response to it.

"Since 1980 (when Republican Ronald Reagan released just one year of returns) only one party nominee or presumptive nominee other than Romney has released fewer than six years of returns, according to PolitiFact. That was Republican John McCain, who released two years of returns in 2008."

So expect to hear more from Democrats about why they think Romney should give more information.

Update at 2:40 p.m. ET. Medical Information Will Be Posted Too:

The campaign says that "in addition to new documents related to tax filings, the campaign will also be posting on the same website physician letters for both Gov. Romney and Rep. Ryan, making public their current state of health."

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